help with ?s on both my mustangs

[itsdamadhatter]

ok 1st
82 5.0, i just swapped motor out for roller, same tranny, the engine came from i believe a 88 fi car, the housing behind the water pump where the mechanical fuel pump went is blocked off on the fi car, now instead of swapping them out can i install a inline fuel pump, or something, im keeping the engine carbed but would rather change the fueling ....

2nd
90 5.0, just got the car it was a 4cyl swap is from 87 gt, with cobra intake manifold on it, the wire harness looks like everything was done right, theres isnt a mass air sensor on the car and when it starts i get an intake pop and when it clears out the idle jumps up and down, im hoping thats just the sensor though so the cobra one im getting ready to order will correct that, next if the car is off and key on acc. the horn button wont honk it runs the fuel pump??????, not to big of a deal because the fuel pump operates normally so im just gonna run new wiring to the horn, the turn signals work but if the headlights are on they wont, the turn signals i guess are wired with the running lights so headlights on turns all the lights on, so im trying to find the best way to fix that. thanks for any help

 

[86bluecobra]

You can run an electric fuel pump for your 82 mustang. Remember that fuel pumps are typically pushers not pullers so you will want to mount the pump as close to the tank as possible. A regulator would also be a good idea to keep your 7psi running to your carb.

 

[88mouse]

on your 4 cyl. swap the 90 wiring harness is different. The 87 wiring harness isn't going to work right. You can buy the right one. There is a place down the road from me that sells them for about $240 brand new.

 

[itsdamadhatter]

how can i tell which harness they used on the swap? and the headlight harness is seperate too right so i can just swap that out?,

now with the fuel pump i can get the pump all the way to the gas tank i was just trying to avoid putting a pump in the tank.

 

[jrichker]

90 5.0, just got the car it was a 4cyl swap is from 87 gt, with cobra intake manifold on it, the wire harness looks like everything was done right, theres isnt a mass air sensor on the car and when it starts i get an intake pop and when it clears out the idle jumps up and down, im hoping thats just the sensor though so the cobra one im getting ready to order will correct that, next if the car is off and key on acc. the horn button wont honk it runs the fuel pump??????, not to big of a deal because the fuel pump operates normally so im just gonna run new wiring to the horn, the turn signals work but if the headlights are on they wont, the turn signals i guess are wired with the running lights so headlights on turns all the lights on, so im trying to find the best way to fix that. thanks for any help

"the horn button wont honk it runs the fuel pump??????, "

Due to your sentence construction, you made it sound like the horn button runs the fuel pump. Is that what you meant?

Good capitalization and punctuation will help make sure that you are not misunderstood. They will also help to get your problems resolved quicker.

There are only about 4 people on Stangnet who attempt to troubleshoot electrical problems and two of them are seldom here online. That leaves me and one other person. So if you want top quality help, be more careful about your grammar.

Just in case your problem is that the horns don't work, here are some tips.

The horn circuit has a button that supplies ground, a relay that uses the button to switch the horns on and off, and two horns. The relay reduces the current that the horn button has to carry. This makes it possible to use a small and simple swich and slip ring on the steering wheel.

The horns typically develop an internal short to ground, which causes the fuses to blow.

The horns are located under the car on the driver's side, forward of the front wheel well. Disconnect BOTH horns, replace the fuse: if the fuse blows immediately, the problem is most likely in the cigar lighter circuit. If not, then press the horn button on the steering wheel: if the fuse blows the problem is in the wiring between the horn relay and the horn. If doesn't blow when you press the horn button, connect ONE of the horns and try again. If it still doesn't blow the fuse, connect the other horn. Chances are that the first horn you re-connect will blow the fuse. Whatever horn blows the fuse at this point has an internal short and is trash. Time for a trip to the junkyard...

 

[itsdamadhatter]

awsome, yes the horn doesnt work, when the button is pressed i can hear the relay under the dash click, and thats it, if i put the ignition of acc, and push the horn the fuel pump will prime for few seconds and then shut off, but if the car is just being started the fuel pump operates as it should,so the problem isnt the fuel pump. I was wondering where could the horn circuit pass over the fuel pump?

 

[Mustang78]

check under the hood to see if there is even a horn..if so put power to the + terminal and ground the case..the oddball wiring was probably the guys fault who did the swap, look at wiring diagrams and get out your glasses!

~Mark~

 

[jrichker]

awsome, yes the horn doesnt work, when the button is pressed i can hear the relay under the dash click, and thats it, if i put the ignition of acc, and push the horn the fuel pump will prime for few seconds and then shut off, but if the car is just being started the fuel pump operates as it should,so the problem isnt the fuel pump. I was wondering where could the horn circuit pass over the fuel pump?

The horn and fuel pump are not electrically connected in any way on the stock wiring plan.

The computer turns the fuel pump on to prime the system for a few seconds and then turns it off. This is by design, and prevents flooding when the engine is cranking. Once the computer sees enough RPM’s that it knows the engine is running, it turns the fuel pump on continuously.

 

[itsdamadhatter]

thanks for all the help, i did look behind the fender there is a horn, now ive found a headlight harness on ebay but what year would i need the 87 for the motor, or the 90 for the car? im thinking its for the 87 right?

 

[93 LX]

you need the harness for the body year not engine year.

Allen

 

[itsdamadhatter]

ok well that harness what does it run too normally? on the left side of my bay it runs to the alternator, and the other side goes to the radiator overflow bottle.and a few other things but thats pretty much correct right?